Molding machines



MOLDING MACHINES 4 Sheets-Sheet l Filed Feb 9. 1967 FIG nNvENToRs THOMASA. CHURCH GEORGE D. DAVIS Nov. 18, 1969 T, A CHURCH l-:T AL

MOLDING MACHINES 4 Sheets-Sheet 2 Filed Feb. 9, 1967 nil lax..

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BY /M,

ATTORNEYS Nov. 18, 1989 T, A CHURCH TAL 3,478,812

Y MOLDING MACHINES Filed Feb. 9, 1967 4 sheets-sheet INVENTORS THOMAS A.CHURCH GEORGE D. DAVIS ATTORNEYS. Y Y v Nov. 18, 1969 Filed Feb. 9, 1967T. A. CHURCH ET AL 3,478,812

MOLDING MACHINES 4 Sheets-Sheet 4 INVENTQRS THOMAS A,cHURcH GEORGE D,DAVIS ATTORNEYS United States Patent O U.S. Cl. 164-183 11 ClaimsABSTRACT OF THE DISCLOSURE The foundry machine disclosed herein includesirnproved and novel facilities for adapting, supporting and inverting amatch plate while enabling convenient insertion of and removal of thematch plate from the machine as well as novel and improved facilitiesfor elevating, squeezing, and impacting the sand mold formed by themachine.

This invention is directed to improvements in molding machines utilizedin foundries and is particularly directed to that class of machne whichmay operate automatically or semi-automatically in order to properlymake sand molds.

Molding machines of this general type have been known for many years.Many of them include some table which is operated by power to lift amold flask together with a pattern plate or match plate upward to aposition where a charge of sand is received by the flask. After thecharge of sand has been received in the flask, the sand is usuallysqueezed tightly within the -flask to make the desired mold. Some priorart machines have used some mechanism for imparting impacts orvibrations to the flask during the squeezing operation so as to furtherenhance the flow of sand within the flask to effect the desiredcompaction and uniformity of sand distribution. Some other machines haveused a mechanism for jolting the flask prior to the squeezing operation.These jolting machines are oftentimes very heavy and expensive. Afterthe sand has been compacted to the desired hardness and density, thematch plate or pattern plate is drawn from the mold flask. Thereafter,the machine may be operated to form another mold in another flask. Insome prior machines, supporting mechanism has been provided to enableinversion of a match plate, as by rotating it through 180, after thematch plate has been removed or drawn from the sand and/or flask. Thisis done in order to enable selective manufacture of cope halves and draghalves of the mold, with the flask defining the cope half being usedwith the impression on one side of the match plate, while the flask fordefining the drag half of the completed mold is used with the impressionor configuration on the other side of the match plate.

Prior machines of the impact-squeeze type have operated satisfactorilybut they may not always compact the sand to the hardness and densitydesired by the foundry operator. Also, while machines of this type haveheretofore been operated satisfactorily, the mechanism therein forsupporting and rotating a match plate is subject to some operatingdifficulties, namely, the operation of locating and changing matchplates or pattern plates is cumbersome. 1

With the foregoing in mind, the major purposes of the present inventionare to provide simple and effective means for lifting a mold flask andsqueezing sand therein while enabling the selective use of impact forcesto properly cause flow of sand for compaction to the desired hardnessand density, the machine being so formed that it enables a rapid andpositive roll-over of a match plate by the machine with simple mechanismfor locating and changing a match'plate at the same time the machine isso designed and arranged that it is easily adaptable to fully automaticor semiautomatic operation to enable the proper compaction of the sanddesired to the same degree in each of a plurality of successivemold-forming operations, these and other purposes of the invention beingmore apparent in the course of the ensuing specification and claims whentaken with the accompanying drawings in which:

FIGURE 1 is a front view of the mold machine incorporating theprinciples of the present invention;

FIGURE 2 is a side view of the machine illustrated in FIGURE 1;

FIGURE 3 is an enlarged view, with certain parts in section for purposesof clarity, of the lifting and impacting facilities for the match plateand mold illustrated in FIGURE 1;

FIGURE 4 is a plan view of a match plate assembly utilized in themachine illustrated in FIGURES 1 and 2;

FIGURE 5 is a detail view, with certain parts in section for purposes ofclarity, of a portion of the match plate supporting and adaptingfacilities utilized in the machine of FIGURES 1 and 2;

FIGURE 6 is a top view of a supporting element utilized to support thematch plate illustrated in FIGURES 1 and 2;

FIGURE 7 is a side view of the element illustrated in FIGURE 6;

FIGURE 8 is a top view of another supporting element utilized with thematch plate assembly utilized in the machine of FIGURES 1 and 2; and

FIGURE 9 is a detail view of a drive connection.

Like elements are designated by like characters throughout thespecification and drawings.

With specific reference now to the drawings and in the first instance toFIGURE 1, the numeral 10 generally designates a support which is adaptedto rest on the foundry floor. A plurality of upstanding supportingstandards 11 are fixed to the support 10 for purposes of supportingother elements of the machine illustrated in FIGURES 1 and 2. The4elements 11 are in the form of cylindrical rods and are positioned inspaced relation so as to define the corners of a rectangle as viewedfrom the top.

An elevating and supporting table 12 is supported on the piston rods 13of a pair of upstanding hydraulic elevating cylinders 14. The hydrauliccylinders 14 are supported on opposite sides of a central guidingassembly generally designated at 15. The -guiding assembly 15 includes aguide piston 16 which is slidably received within the cylindrical boreof an upstanding member 17 which is fixed to the support 10. Uponoperation of the elevating cylinders 14, table 12 may be reciprocatedvertically.

Table 12 forms a support for a pattern stool 18 which is fixed to thetop of table 12. The pattern stool 18 serves to support a match plateassembly generally designated at 19. Supports 20 for a mold flask 21 arepositioned at a level above the at rest position of stool 18 shown inFIGURE 1. The supports 20 are adjustably clamped to the standards 11 andmay include a plurality of rollers 22 in spaced relation to define arolling conveyor track for the mold flask 21. It should be understoodthat the guides 20 may be extended laterally beyond each side of themachine illustrated in FIGURE 1 to any desired length to accommodate anydesired number of mold flasks. The supports 20 may be adjustedvertically on standards 11 to a selected fixed position. This adjustmentmay be made to accommodate mold flasks of different height and providesand adjustable draw of the pattern plate from the mold flask.

An upset frame 23 is adapted to be supported above the mold flask as bymeans of brackets 24 `carried in an adguides 20 and above the mold flask21 when the parts are in the position illustrated in FIGURE 1. Thevertical adjustment of brackets 24 may be made in accordance with thedesires of the operator, with or without adjustment of the clamps forsupport 20. The upset frame 23 may include pins 25 which rest inrecesses 26 in the brackets 24 so that as the mold flask 21 is movedupwardly into engagement with the upset frame 23, the upset frame 23 issimply moved upwardly with the mold ask 21 toward a reaction framegenerally designated at 27. The reaction frame may be supported byrollers 28 which ride along parallel rods 29 extending at opposite sidesof the machine above the upset frame brackets 24. The rods 29 may besupported by brackets 30 fixed to the standards 11. The reaction frame27 is adapted to be reciprocated to and from the full line and dottedline positions illustrated in FIGURE 2 through a power means which isnot shown in the drawings. Although not shown in the drawings, it shouldbe understood that sand hopper facilities are positioned above the upsetframe 23 and above the reaction frame 27 in vertical alignment with themold ask 21 and table 12 so as to charge a ask positioned beneath thehopper facilities with foundry sand.

The match plate assembly which is generally designated at 19 in FIGURE 1may include an adapter plate 31 which is illustrated in FIGURE 4.Adapter plate 31 is in the form of a generally rectangular plate witharms 32 extending outwardly at opposite sides thereof. The interior ofthe plate is cut out in the configuration illustrated by the interiorwall 33 dening an opening corresponding to the configuration of a matchplate. A match plate having a mold pattern P on opposite sides thereofis then positioned within this opening and pins generally designated at34 are passed through bores in the walls of the adapter 31 and intomatching recesses in the sides of the match plate in order to hold thematch plate within the adapter plate 31. The pins 34 may take the formof bolts or screws. Additional pins may be used in the other walls ofthe adapter plate.

Recesses 36 are formed in the arms 32 to accommodate circular bushings37 which are formed and dimensioned to receive the pins in a drag moldhalf. The opposite side of the arm carries a pin 38 which is formed anddimensioned to -be received in the recess of a cope ask, which recessnormally receives the pin of the drag ask. A similar pin and bushingassembly is provided in each arm 32. An additional recess is formed ineach arm 32 outwardly of the bushing and pin assembly and serves tosupport another bushing 39 for purposes of receiving upstanding locatorpins 39a. The bushings 39 provide apertures which receive locator pins39a carried in upstanding relation on arms 39h affixed to the sides ofthe stool 18. The pins 39a serve to properly align the adapter plate 31with the mold flask and at the same time allow simple and convenientremoval of the adapter plate and match plate from the machine. Thelocator pins 39a may be made of any height desired and serve to properlylocate the adapter plate regardless of the spacing of the adapter platefrom the pattern stool 18, as long as the pins are engaged with thebushings. The outer ends of each arm 32 are provided with spacedapertures 40 which apertures receive pins 41 which are passedtherethrough and through apertures 42 in the legs of a roll-overtrunnion. One trunnion 44l which is seen in FIGURES 5 and 6 is a drivetrunnion'. The legs 43 of the roll-over trunnion 44 embrace the arms onopposite lsides thereof and when the pins 42 are passed through thealigned apertures in the arm 32 and the legs 43 of the roll-overtrunnion, the trunnion is locked to the adapter plate. The drivetrunnion illustrated at the right hand side in FIGURE 1 includes acylindrical bearing portion 45 and a generally rectangular lug portion46. The other trunnion 47 which appears in FIGURE 8 may be identical totrunnion 45. It includes a cylindrical bearing portion 47a andpreferably, the end of this trunnion is made generally cylindrical. Theanged portions 48 on opposite sides of the bearing structure 45 and 47aof each trunnion provide a stop on opposite sides of the bearing surface45. Trunnion 47 has legs which are identical to the legs 43 of trunnion44 and which are fixed to the other arm 32 in the same manner.

In some cases, the adapter plate 31 may be eliminated and the matchplate itself is then provided with arm structures identical to the armstructures 32 of the adapter plate.

In the inactive position of the match plate assembly, the trunnions 44and 47 rest in upwardly open bearings 49 and 50 positioned on oppositesides of the pattern stool 18 in FIGURE l. These bearings 49 and 50 arecarried by arms 51 and 52, respectively, which arms are slidablysupported on the upstanding standards 11 as by means of sleeves 53 and54. The sleeves 53 and 54 may be connected by a cross arm 55. A powersource, such as a hydraulic cylinder 56, has the piston rod thereofconnected to the cross arm so as to elevate the bearings 49 and 50 andthe plate assembly supported thereon upwardly to a position illustratedin dotted outline in FIGURE 2. When in this position, the match plateassembly may be inverted by means of a rotary hydraulic actuator 57which is supported on arm 52, as for example by means of a platform 58.The rotary hydraulic motor 57 may include a lug fitting 59 on the driveshaft thereof, which tting 59 is recessed to match the configuration ofthe lug 46 of the drive trunnion 44. The lowermost position of the arms51 and 52, which is illustrated in FIGURE l, may be xed by stops for thesleeves 53 and 54, or by the stroke of cylinder 56.

The fitting 59 carried by the shaft of motor or actuator 57 has agenerally U-shaped opening 59a in the end face thereof so as to receivethe projecting lug 46 of trunnion 44. This provides for quick couplingand uncoupling of fitting 59 to the trunnions for purposes of roll-over,insertion and removal of the match plate. At the match plate stool andtable are lifted towards the ask 21, the lug 46 moves out of itsmatching recess 59a and after the mold has been formed and the matchplate 19 de- -scends with the stool 18, the trunnions move into theirupwardly open bearings 49 and 50 while the lug 46 enters its matchingrecess 59a in the drive element 59.

Table 12 may be secured to the guide piston 16 by means of cap screws orlike 77. The portion of the cylinder 17 beneath piston 16 may be closedby a lower cover plate 76 when it is desired to use the lower portion ofthe guide cylinder for auxiliary lifting or squeezing purposes.

The piston rods of the hydraulic elevators 13 may be secured to thetable by means of cap screws or the like 78. A plug, not shown, may beused to close the threaded opening in the top of the table appearing at79 and leading to pressure chamber 72.

Actuator 57 is a type which rotates its shaft 180 and then stops.

When the motor 56 is actuated to elevate the match plate assembly to theposition illustrated in FIGURE 2, the match plate assembly is at aheight sucient that it may be inverted by the actuator 57 after whichtime the motor 56 lowers the match plate assembly to the inactiveposition illustrated in FIGURE 1. In this position, the adapter andmatch plate may be positioned some distance ab/e the pattern stool 18 orit may be in contact therew1 IIn the active position of the match plateassembly, the

v motors 1.4 elevate the table 12 and pattern stool so as to contact thematch plate assembly 19 and lift it upwardly into engagement with theunderside of a mold flask positioned thereabovevand in vertical registrytherewith-As the assembly continues its upward movement, the mold ask 21is lifted above the rollers 22 and brought into engagement with theupset frame 23. The upward movement continues to a sand-filling positionwhere the flask receives a charge of sand and then the reaction membermoves forwardly or to the full line position illustrated in FIGURE 2where excess sand, if any, is struck off by t'he reaction member 27. Thehydraulic cylinders or elevators 14 then continue their upward movementso as to squeeze the sand in the mold flask against the reaction head27. Impact forces, as later described, may then be delivered to themold, -at the selection of the operator. When the assembly is thenlowered, the upset frame moves down to a point where it is received inthe brackets 24 therefor, the mold flask 21 moves down to a point wherethe flanges thereof engage the rollers 22. The match plate assembly isdrawn from the flask 21 and moves down to a point where the trunnionsare lengaged by and supported in the bearings 49 and 50 in thesupporting arms 51 and 52.

When the match plate assembly has been returned to the lower positiongenerally illustrated in `FIGURE l, the cylinder 56 may be actuated toagain raise the match plate assembly whereupon the actuator 57 mayinvert the same to enable the alternate formation of cope halves anddrag halves of the mold. In some cases, of course, a plurality of copehalves may be made before the match plate is inverted to make aplurality of drag halves.

The guide assembly is formed with means to enable power impact strokeson the lower surface of the table 12 before, during or after the squeezecycle of the machine. To this end, the guide piston 16 is formedgenerally as a cylinder, the upper portion of which carries acylindrical impact member 60 therein. Impact member 60 carries a wearring 61, which is adapted to impact the lower surface of the table 12.The lower portion of the cylinder 60 carries a depending stem 62 whichis slidably received through a bearing 63 and seal `63a in a portion 64of the guide piston. The space below guide stem 62 is closed by a coverplate -65 so that a pressure chamber 66 may be defined above the coverplate 65 but below the guide stem 62 while a second pressure chamber 67may be defined below the cover plate 65.

An internal bore of the impact cylinder 60 is in slidable engagement-with a depending, hollow stem 68 of table 12. A first inlet port 69 isin communication with the chamber 66 and is supplied with air underpressure through a passage leading through the guide piston andconnected to an external source of pressure (not shown). A second inletport 70 is formed in the hollow interior of the stem 68 and is adaptedto direct air pressure against the upper surface of the stem 62 as bymeans of the passages 71. The space above stem 62 and beneath the steml68 defines another pressure chamber 72 which is supplied -with pressurefrom the inlet port 70. The area of the upper surface of the guide stem62 exposed to the pressure in chamber 72 is preferably greater than thearea at the lower surface of the guide pin 62 which is subjected to thepressure in the chamber `66. The'areas are such, with relation to theweight of impact member 60, that -whenpressure is supplied to both inletports 69 and 70, the result will be to force stem or guide pin 62 andcylinder 60 to which it is affixed downwardly.

As an aid in directing pressure against the upper portion of the guidepin or stem 62, passagesy 73 may be formed in the wall of the impactcylinder and receive air from inlet ports 73a in stem 68.

'Exhaust ports 74 are formed through the impact cylinder'and lead fromthe internal bore therein to the outside. During operation of themachine, air pressure is introduced and `maintained at inlet port 69 inguide piston 16. This pressure results in an upward force acting on thelower end of the guide pin 62. This force causes the assembly` of theguide pin 62, impact cylinder 60 and wear ring 61 to raise until thewear ring 61 contacts the under side of table 12. The assembly is now inthe position as shown in FIGURE 3. The assembly of the guide pin,cylinder and wear ring are gui-ded throughout this 'upward movement, andthrough the subsequent 6 downward movement by the stem 68 of the innerwall of guide piston 16.

The impact section is caused to operate by introducing air pressurethrough intake port 70. This pressure and air flow through the stem 68to the ports 73 in impact cylinder 60, and into pressure chamber 72.

Because the force against the top of guide pin 62 is greater than theforce against the bottom (pressure chamber 72 area of the pin 62 isgreater than pressure chamber 66 area of the pin 62), the assembly ofthe gui-de pin 62, impact cylinder 60 and ywear ring 61 is caused tomove downward. This downward movement is controlled by the location ofexhaust ports 74. After a predetermined downward movement, the exhaustports become open to the pressure chamber 72. The pressure dropresulting in pressure chamber 72 lessens the amount of downward forceagainst guide pin 62. Therefore, the assembly 62, 60 and `61 are causedto travel rapidly upward until the wear ring 61 against c-ontacts thebottom anvil surface of table 12. This contact imparts a hard impactforce to the bottom anvil surface of table 12. During the final upwardtravel of the assembly, the exhaust ports 74 are again closed, allowingpressure to build up again in chamber 70. Full pressure again causes theassembly to start downward again. This alternate downward and upwardmotion is continued until the pressure is removed from port 70 in table12. The assembly may operate to provide for a number of identical impactstrokes during each second of time that pressure is supplied to port 70.

The squeeze cylinders 13 will cause the guide piston and its internalparts to move up in guide cylinder 17. The length of guide cylinder 17and guide piston 16 is such that an extremely accurate movement upwardand downward is obtained.

During the squeeze movement provided by cylinders 14, the impact sectionmay be operated. The position of the squeeze has no effect on the impactsection. It may be operated before, after or at any time through thecomplete movement of the squeeze.

An additional squeezing force may be imparted to the table 12 as byadmitting air pressure through a port 75 in chamber 67 below cover plate65. By use of this pressure, the squeezing force applied to the moldflask and reaction member may be v-aried by varying or omitting thepressure supplied through port 75.

By reason of the use of the locator pins 39a for the match plateassembly, the adapter plate and match plate are easily removed from themachine by simple upward vertical movement and a new and different matchplate assembly is easily inserted in converse fashion. At the same time,the locator pins 39a allow the adapter plate and match plate to bestopped at any convenient position above the stoll 18. Thus in the atrest position, the adapter plate may be supported solely on the bearings49 and 50 and held in proper position by the locator pins 39a. This hasthe advantageous result of shortening the automatic molding cycle timebecause of the match plate and adapter plate are required to move fullyto the lowermost position with the table 12 before the match plate canbe inverted, this requires additional cycling time even though only afraction of a second may be involved, depending upon the overall speedof the machine. When spaced above the stool, the adapter plate does nothave to rise as far to clear the stool as it does when it is supportedon the stool. Elevation of the match plate for rollover purposes canstart before the stool have moved to the lowermost position. The matchplate may be stopped at any selected distance above the stool and heldin the at rest position by making the locator pins 39a of the properlength.

Through use of the bushings 37 and pins 38, the adapted plate isaccurately located to the mold ask, whether the flask be a cope half ora drag half.

By reason of the squeeze cylinders 14 which are independent of theimpact assembly beneath table 12, the

impact strokes imparted by the impact assembly may be operated at anytime during the squeeze portion of the cycle or may, in fact, beoperated during the filling of the mold flask and before the squeezeportion of the cycle commerces. It should be noted in this regard thatthe impact forces imparted to the table and hence to the mold flask arehighly effective in causing lateral movement of the sand in the moldflask.

Automatic cycling and control equipment, not shown or described hereincan be conveniently set up so as to allow an operator to select the timeat which impact starts and the duration thereof either before, after, orat some time during the squeezing portion of the cycle.

By using the lower portion of the guide cylinder and piston as anauxiliary source of squeezing pressure, additional squeezing forces maybe selectively utilized. This additional squeezing force may becontrolled so that the operator can easily select the time at which theadditional squeezing force is imparted to the sand in the mold. Forexample, in some cases the operator may wish to use the additionalsqueezing force at the start of the squeeze operation. In other cases,he may wish to use the additional squeezing force during a laterinterval in the squeeze portion of the mold forming cycle.

The particular arrangement shown herein provides extreme versatility ofthe machine and allows a wide range of selective forces which may beimparted to the mold during the mold forming cycle.

The match plate supporting mechanism and power means for inverting thematch plate are entirely separate from the remainder of the machinealthough as a matter of convenience the guides 53 and 54 are mounted onthe standards for the machine. The actuator 47 for effecting inversionof the match plate assembly may be tied in with the same electricalcontrol circuit as that which is used in controlling the elevating,squeeze, and impact operation so that at or near return of the table tothe lowermost position, actuator 57 is automatically operated to invertthe match plate after which time table 12 may be caused to automaticallyrise for the start of another mold forming operation. Thus, the machinemay be easily adapted to the alternate or selective formation of copehalves and drag halves.

Whereas we have shown and described an operative form of the invention,it should be understood that this showing and description thereof shouldbe taken in an illustrative or diagrammatic sense only. There are manymodifications in and to the invention which will fall within the scopeand spirit thereof and which will be apparent to those skilled in theart. The scope of the invention should be limited only by the scope ofthe hereinafter appended claims.

We claim:

1. Supporting mechanism for elevating and impacting a mold flaskincluding a vertically reciprocable support in a molding machine frame,said support being formed and adapted to engage an assembled mold flaskand pattern element for raising and lowering the same, said supporthaving a depending portion telescopically received within a guide sleevefor vertical sliding movement therein, hydraulic means for lifting andlowering said support, and separate fluid pressure means within saidportion and operable against an element vertically movable therein tocause reciprocation of said element into and out of contact with theundersurface of said support for selectively imparting impact forces tothe undersurface of said support independently of said hydraulic means.

2. The structure of claim 1 wherein said last named means includes twofluid chambers defined within said depending portion and an impactelement within said member formed and adapted for reciprocation againstthe undersurface of said support, said element having different areasexposed to the pressure within each of said chambers, fluid pressuremeans adapted to supply fluid pressure to both of said chambers wherebyupon supply of pressure to both of said areas, said impact member willbe moved in one direction and exhaust means for the chamber exposed tothe larger one of said areas and formed and adapted to be opened after apredetermined amount of movement in said direction and to be closed inother positions of movement whereby said impact element Will beautomatically reciprocated against and away from said support to providesuccessive impact forces as long as pressure fluid is supplied to thechamber exposed to the larger area.

3. In a molding machine for foundry use, means for supporting a moldflask, a support for engaging and lifting a mold flask and match plateassembly positioned beneath said mold flask, means for elevating saidSupport to engage and carry an assembled match plate and mold flask intoa sand filling position, separate support and elevating means forsupporting said match plate in a lowermost inactive position, said firstnamed support being positioned below and out of contact with said matchplate in a lowermost, inactive position, said match plate including asupport with trunnions on `opposite sides thereof, said separate supportand elevating means including a pair of arms having upwardly openbearings adapted to receive said trunnions of said match plate, andpower means carried thereby for engaging one of said trunnions andselectively rotating the same so as to invert said match plate, saidpower means being separate from both of said elevating means.

4. A mechanism for supporting a match plate assembly in a moldingmachine including a support of the type used to elevate a pattern platetoward a superposed mold flask, said support having upstanding pins atopposite sides thereof, a match plate assembly in overlying relation tosaid support and having apertures in vertical alignment with said pins,said pins being extended through said apertures, said match plateassembly having trunnions received in upwardly open bearings carried bysaid machine, and power means for elevating said match plate assemblyfrom said support and pins and for effecting inversion thereof, saidpower means including a driving actuator with a drive lug engaged withone of said trunnions, said one trunnion and drive lug havinginterfitting projection and recess portions which are formed to allowdisengagement thereof upon relative movement of said lug and trunnionnormal to the axis lof rotation of said lug and trunn1on.

5. The structure of claim 4 wherein said match plate assembly includesan adapter plate and a match plate held within and supported by saidadapter plate, said adapter plate having laterally extended arms, saidtrunnions being detachably coupled to said arms. K

A6. A molding machine for foundry use and of the type wherein asupporting table is used to elevate a pattern plate into engagement withthe undersurface of a mold flask so as to lift the pattern plate andmold flask to a sand filling position, the improvement comprising aguiding piston with a bore therein received within a cylindricalsupporting member, a pattern elevating table supported on said piston,an impact cylinder positioned in an upper portion of a bore in saidguide piston, means supporting said impact cylinder for axial movementin said piston, said impact cylinder including a depending element atthe lower portion thereof, meansl defining separate upper and lowerpressure chambers exposed to upper and lower pressure areas,respectively of 'said element, the area of said element exposed to theupper chamber being greater than the area of the element exposed to thelower pressure chamber, exhaust means for said upper chamber, means forclosing said exhaust means when said impact cylinder is located atpositions adjacent the undersurface of said table, and means for openingsaid exhaust means when said impact cylinder is below said positionswhereby the force developed in said lower chamber causes said impactcylinder to move upwardly and impact against said table and the forcedeveloped in said upper chamber after impact against said table causessaid impact cylinder to move downwardly until said exhaust means isopened for a subsequent upward movement of said impact cylinder, andsepaarte hydraulic cylinders for elevating said table and effecting asqueezing of sand in a mold ask.

7. A molding machine for foundry use and of the type wherein asupporting table is used to elevate a pattern plate into engagement withthe undersurface of a mold lask so as to lift the pattern plate and moldask to a sand lling position, the improvement comprising a guidingpiston with a bore therein received within a cylindrical supportingmember, a pattern elevating table supported on said piston, an impactcylinder positioned in an upper portion of the bore of said piston, saidtable having a depending guide stem, said impact cylinder having ahollow bore and being slidably mounted on said guide stern, said impactcylinder including a depending element at the lower portion thereof andspanning the bore in said impact cylinder, means defining upper andlower pressure chambers exposed to upper and lower pressure areas ofsaid element, the area of said element exposed to the upper chamberbeing such, with relation to the weight of said impact cylinder, thatthe resultant forces cause said impact cylinder to move downwardly whenboth areas are subjected to the same fluid pressure, and an exhaust portformed through said impact cylinder and opening into the chamber abovesaid element when said impact cylinder is located at positions below aposition substantially near the undersurface of said table, and meansfor closing said exhaust port when said impact cylinder is between saidlast named position and a position in engagement with the undersurfaceof said table whereby the force developed in said lower chamber causessaid impact cylinder to move upwardly and impact against said table, andseparate hydraulic means for elevating said table.

`8. The structure of claim 7 wherein said impact cylinder includes awear ring on the upper surface thereof.

9. The structure of claim 7 wherein the space below said guide piston isa pressure chamber to apply elevating forces to said piston.

10. Foundry apparatus for supporting and inverting mold apparatus of thetype having spaced and generally aligned supporting trunnions and spacedlocater apertures and wherein one of said trunnions has a noncircularcross-sectional portion including a support having spaced and alignedupwardly open bearings for receiving coaxial trunnions of moldapparatus, power means for elevating and lowering said support, meanssupporting spaced, upstanding locater pins at a position generallyhorizontally aligned with said bearings when said rst named support isina lower position, and a rotatable motor carried by said lirst namedsupport including a rotatable, driven, connecting element generallyaligned with one of said bearings, said connecting element having across-sectional portion matching said trunnion portion and being formedand adapted for a releasable engagement with said one trunnion portion,said connecting element portion being positioned to receive saidtrunnion portion in an intertting relation when said trunnions arereceived in said bearings.

11. The structure of claim 10 wherein said connecting element is in theform of a slotted lug.

References Cited UNITED STATES PATENTS Oyster 164-409 X I. SPENCEROVERHOLSER, Primary Examiner I. I. BROWN, Assistant Examiner U.S. C1.X.R. 164-207

